diff options
| -rw-r--r-- | drivers/pci/hotplug/pciehp_hpc.c | 36 | ||||
| -rw-r--r-- | drivers/pci/pci.h | 4 | ||||
| -rw-r--r-- | drivers/pci/pcie/dpc.c | 74 |
3 files changed, 109 insertions, 5 deletions
diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c index fb3840e222ad..9d06939736c0 100644 --- a/drivers/pci/hotplug/pciehp_hpc.c +++ b/drivers/pci/hotplug/pciehp_hpc.c @@ -563,6 +563,32 @@ void pciehp_power_off_slot(struct controller *ctrl) PCI_EXP_SLTCTL_PWR_OFF); } +static void pciehp_ignore_dpc_link_change(struct controller *ctrl, + struct pci_dev *pdev, int irq) +{ + /* + * Ignore link changes which occurred while waiting for DPC recovery. + * Could be several if DPC triggered multiple times consecutively. + */ + synchronize_hardirq(irq); + atomic_and(~PCI_EXP_SLTSTA_DLLSC, &ctrl->pending_events); + if (pciehp_poll_mode) + pcie_capability_write_word(pdev, PCI_EXP_SLTSTA, + PCI_EXP_SLTSTA_DLLSC); + ctrl_info(ctrl, "Slot(%s): Link Down/Up ignored (recovered by DPC)\n", + slot_name(ctrl)); + + /* + * If the link is unexpectedly down after successful recovery, + * the corresponding link change may have been ignored above. + * Synthesize it to ensure that it is acted on. + */ + down_read(&ctrl->reset_lock); + if (!pciehp_check_link_active(ctrl)) + pciehp_request(ctrl, PCI_EXP_SLTSTA_DLLSC); + up_read(&ctrl->reset_lock); +} + static irqreturn_t pciehp_isr(int irq, void *dev_id) { struct controller *ctrl = (struct controller *)dev_id; @@ -707,6 +733,16 @@ static irqreturn_t pciehp_ist(int irq, void *dev_id) } /* + * Ignore Link Down/Up events caused by Downstream Port Containment + * if recovery from the error succeeded. + */ + if ((events & PCI_EXP_SLTSTA_DLLSC) && pci_dpc_recovered(pdev) && + ctrl->state == ON_STATE) { + events &= ~PCI_EXP_SLTSTA_DLLSC; + pciehp_ignore_dpc_link_change(ctrl, pdev, irq); + } + + /* * Disable requests have higher priority than Presence Detect Changed * or Data Link Layer State Changed events. */ diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h index 37c913bbc6e1..dac6922553b4 100644 --- a/drivers/pci/pci.h +++ b/drivers/pci/pci.h @@ -385,6 +385,8 @@ static inline bool pci_dev_is_disconnected(const struct pci_dev *dev) /* pci_dev priv_flags */ #define PCI_DEV_ADDED 0 +#define PCI_DPC_RECOVERED 1 +#define PCI_DPC_RECOVERING 2 static inline void pci_dev_assign_added(struct pci_dev *dev, bool added) { @@ -439,10 +441,12 @@ void pci_restore_dpc_state(struct pci_dev *dev); void pci_dpc_init(struct pci_dev *pdev); void dpc_process_error(struct pci_dev *pdev); pci_ers_result_t dpc_reset_link(struct pci_dev *pdev); +bool pci_dpc_recovered(struct pci_dev *pdev); #else static inline void pci_save_dpc_state(struct pci_dev *dev) {} static inline void pci_restore_dpc_state(struct pci_dev *dev) {} static inline void pci_dpc_init(struct pci_dev *pdev) {} +static inline bool pci_dpc_recovered(struct pci_dev *pdev) { return false; } #endif #ifdef CONFIG_PCIEPORTBUS diff --git a/drivers/pci/pcie/dpc.c b/drivers/pci/pcie/dpc.c index e05aba86a317..c556e7beafe3 100644 --- a/drivers/pci/pcie/dpc.c +++ b/drivers/pci/pcie/dpc.c @@ -71,6 +71,58 @@ void pci_restore_dpc_state(struct pci_dev *dev) pci_write_config_word(dev, dev->dpc_cap + PCI_EXP_DPC_CTL, *cap); } +static DECLARE_WAIT_QUEUE_HEAD(dpc_completed_waitqueue); + +#ifdef CONFIG_HOTPLUG_PCI_PCIE +static bool dpc_completed(struct pci_dev *pdev) +{ + u16 status; + + pci_read_config_word(pdev, pdev->dpc_cap + PCI_EXP_DPC_STATUS, &status); + if ((status != 0xffff) && (status & PCI_EXP_DPC_STATUS_TRIGGER)) + return false; + + if (test_bit(PCI_DPC_RECOVERING, &pdev->priv_flags)) + return false; + + return true; +} + +/** + * pci_dpc_recovered - whether DPC triggered and has recovered successfully + * @pdev: PCI device + * + * Return true if DPC was triggered for @pdev and has recovered successfully. + * Wait for recovery if it hasn't completed yet. Called from the PCIe hotplug + * driver to recognize and ignore Link Down/Up events caused by DPC. + */ +bool pci_dpc_recovered(struct pci_dev *pdev) +{ + struct pci_host_bridge *host; + + if (!pdev->dpc_cap) + return false; + + /* + * Synchronization between hotplug and DPC is not supported + * if DPC is owned by firmware and EDR is not enabled. + */ + host = pci_find_host_bridge(pdev->bus); + if (!host->native_dpc && !IS_ENABLED(CONFIG_PCIE_EDR)) + return false; + + /* + * Need a timeout in case DPC never completes due to failure of + * dpc_wait_rp_inactive(). The spec doesn't mandate a time limit, + * but reports indicate that DPC completes within 4 seconds. + */ + wait_event_timeout(dpc_completed_waitqueue, dpc_completed(pdev), + msecs_to_jiffies(4000)); + + return test_and_clear_bit(PCI_DPC_RECOVERED, &pdev->priv_flags); +} +#endif /* CONFIG_HOTPLUG_PCI_PCIE */ + static int dpc_wait_rp_inactive(struct pci_dev *pdev) { unsigned long timeout = jiffies + HZ; @@ -91,8 +143,11 @@ static int dpc_wait_rp_inactive(struct pci_dev *pdev) pci_ers_result_t dpc_reset_link(struct pci_dev *pdev) { + pci_ers_result_t ret; u16 cap; + set_bit(PCI_DPC_RECOVERING, &pdev->priv_flags); + /* * DPC disables the Link automatically in hardware, so it has * already been reset by the time we get here. @@ -106,18 +161,27 @@ pci_ers_result_t dpc_reset_link(struct pci_dev *pdev) if (!pcie_wait_for_link(pdev, false)) pci_info(pdev, "Data Link Layer Link Active not cleared in 1000 msec\n"); - if (pdev->dpc_rp_extensions && dpc_wait_rp_inactive(pdev)) - return PCI_ERS_RESULT_DISCONNECT; + if (pdev->dpc_rp_extensions && dpc_wait_rp_inactive(pdev)) { + clear_bit(PCI_DPC_RECOVERED, &pdev->priv_flags); + ret = PCI_ERS_RESULT_DISCONNECT; + goto out; + } pci_write_config_word(pdev, cap + PCI_EXP_DPC_STATUS, PCI_EXP_DPC_STATUS_TRIGGER); if (!pcie_wait_for_link(pdev, true)) { pci_info(pdev, "Data Link Layer Link Active not set in 1000 msec\n"); - return PCI_ERS_RESULT_DISCONNECT; + clear_bit(PCI_DPC_RECOVERED, &pdev->priv_flags); + ret = PCI_ERS_RESULT_DISCONNECT; + } else { + set_bit(PCI_DPC_RECOVERED, &pdev->priv_flags); + ret = PCI_ERS_RESULT_RECOVERED; } - - return PCI_ERS_RESULT_RECOVERED; +out: + clear_bit(PCI_DPC_RECOVERING, &pdev->priv_flags); + wake_up_all(&dpc_completed_waitqueue); + return ret; } static void dpc_process_rp_pio_error(struct pci_dev *pdev) |